Many osteochondral lesions will resolve on their own or with conservative treatment such as reduced work load. But some lesions do require surgical intervention to prevent compromised soundness and performance.

Photo: The Horse Staff

Osteochondral lesions that show up on young horses' radiographs might appear worrisome, but the veterinarian behind a recent research review concluded that surgery isn’t always necessary, or even recommended. And in many cases the worry isn’t necessary either.

“I see far too many situations of positive radiographs meaning a flunked prepurchase exam in a sound horse,” said C. Wayne McIlwraith, BVSc, PhD, DSc, FRCVS, Dipl. ACVS, Dipl. ACVSMR, director of the Orthopaedic Research Center at Colorado State University. “Osteochondrosis defects are not the biggest thing we have to worry about in young horses.”

Often, osteochondral lesions will resolve on their own or with conservative treatment such as reduced work load, he said. But some osteochondral lesions do require surgical intervention to prevent compromised soundness and performance.

McIlwraith recently investigated the outcomes of surgical and nonsurgical care of various osteochondral lesions in a research review. He found that surgery can be beneficial in certain cases, depending on the location and kind of lesion:

Some lesions in the trochlear ridges of the femur in the stifle can improve with conservative treatment even if there is lameness and fluid buildup in the joint at the time of examination—provided the lesions haven’t fragmented and are less than 2 centimeters long, he said.

By contrast, researchers recommend arthroscopic surgery for any lesion in any of the four possible locations for osteoarthritis dissecans (the clinical problem resulting from the osteochondrosis disease process) in the hock joint.

In the fetlocks, the need for surgery (or lack thereof) depends on the kind of lesion: A horse with a Type I lesion (those with no fragments) probably doesn’t need surgery, while a horse with Type II or III (those that are fragmented within the lesion or have an actual loose fragment, respectively) probably do.

Shoulder lesions depend on the location: Select cases limited to the glenoid (socket) typically do not require surgery. However, if it involves the humeral head, surgery is necessary; still, but there is only a 50/50 success rate for these operations.

Horses with subchondral cysts in the femur's medial condyle can often be treated with injection of triamcinolone acetonide (an anti-inflammatory corticosteroid) into the cyst under arthroscopic visualization. The success rate is around 80% for horses with unilateral lesions. And when that doesn’t work, surgical curettage (a procedure in which a surgeon scrapes the cyst's lining to remove debris), sometimes combined with other augmented therapies such as stem cells, can often do the trick, he said.

But all in all, surgery is unnecessary in many cases where radiographic changes are found on routine radiographs of yearlings, McIlwraith said. However, if fragments are present and the yearling is destined for sale, owners generally opt for surgery, he added. The critical factor is whether there are signs of disease and whether the owner wants to sell the horse.

“In most instances where radiographic lesions are seen on survey radiographs (without clinical signs and if no sale is planned), conservative management is recommended,” he stated.

And in fact, he said, regular X ray screening on a horse with no clinical signs might be an unnecessary source of worry, he added.

“Of course, radiographic screening of yearlings for sale is common,” McIlwraith told The Horse. “I don’t disagree with radiographic screening but we also need to pay attention to the clinical signs.”

If X ray surveys are carried out, multiple views of the joint should be taken as described in repository guidelines, he said. Single views of the joint would be too limited and not provide an accurate enough evaluation of the horse’s osteochondral status, he explained.

About the Author

Christa Lesté-Lasserre is a freelance writer based in France. A native of Dallas, Texas, Lesté-Lasserre grew up riding Quarter Horses, Appaloosas, and Shetland Ponies. She holds a master’s degree in English, specializing in creative writing, from the University of Mississippi in Oxford and earned a bachelor's in journalism and creative writing with a minor in sciences from Baylor University in Waco, Texas. She currently keeps her two Trakehners at home near Paris. Follow Lesté-Lasserre on Twitter @christalestelas.

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